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Nov. 3, 1942.

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W. F. STREHLOW TRACTOR Y Filed July 14, 1941` 2 Sheets-Sheet l @www Nov.3, 1942.

w. F. sTREHLow 2,301,152

TRACTOR Filed July 14, 1941 2 sheets-Shen 2 if 6 7s r.. 27 @m5- 5 Z6 lza* za /vw/Q/vxXo/u Patented Nov. 3, 1942 UNITED STATES PATENT OFFICE.

TRACTOR Walter F. Strehlow, Wauwatosa, Wis.. assignor to Allis-ChalmersManufacturing Company, Milwaukee, Wis., acorporation of DelawareApplication July A14:, 1941, Serial No. 402,296!

3 Claims.

among which are: lightness of operation tosavev the operator from unduefatigue; quick responsiveness to permit dodging of plants When thetractor is used for row crop cultivation and similar operations;accurate control of the steering movements of the Wheels or wheel;compactness to save space for mounting implements or attachments on thetractor and to avoid' interference of the mechanism with good visibilityof the ground from the drivers seat or with the crop when the tractor isused for row crop Work; wear protection Without frequent oilings orgreasings by the operator; facility of installation of the mechanism on,and of its removal from the tractor; facility of assembly anddisassembly of the mechanism for inspection, adjustment and repair;simplicity of design; loW manufacturing costs; and dependable operation.Generally stated, it is an object of the invention to provide a steeringmechanism which meets all of these requirements.

More specically, it is an object of the invention to provide an improvedmechanism for rotating a vertically disposed steering vspindle of atractor, the improved mechanism including a steering crank which isrotatable on. an axis extending transversely of the tractonand anendwisereciprocable link at the side of the tractor for rocking the steeringcrank. A Worm vand gear unit of standard automotive designis preferablyemployed to reciprocate the link endvvise, and the steering crank has abevel gear connectionwilh the vertical steering spindle. The arm of thesteering crank to which the link is connected at its forward end swingsabout thementioned transverse axis when the link is reciprocated endwiseby operation of the Worm and gear unit, and the mechanism thereforerequires very little space at the side of the tractor, as compared withan arrangement in which the link' is connected to al laterally extendingarm of the steering spindle, or to an arm of a spur gear segment in meshwith a spur gear pinion on the steering spindle. The actuation of thesteering spindle by means of the mentionedsteering crank which isrotatable about an airis eX- tending transversely of the tractor, hasthe advantage of saving space, at the side ofthe tractor,

for the mounting' of implements or attachments on the tractor,While-permitting atthe same ltime the use-of aworm and gear unit ofstandard automotive design, which, due to mass produc-A tion, isavailable at aA relatively 10W price.

A mechanism employing-aworm and gear unit, link and steering crank in fthe mentionedl mantner, ascontemplated bythe invention; furtherdoes-.notrequire auniversal joint between a'pair of rotatableshafts-such-ashave heretofore-been frequently used intractor steeringmechanisms.`

The elimination of thev mentioned universal joint is another advantagebecause the -exingV of Vsuch aI jointduring actuation ofthe steering"mechanism -tends -to fatigue the operatorduring long periods ofoperation of the tractor. l

YAsstated, the steerable Wheelsy of a tractor are-,usually mounted on afron-t steering truck,

andit is-common practice tomakeadditional` use-ofv thesteering truckbysupportingvthe radiator ofthe tractor thereon. pleasingappearanceandYfor regulating the `passage of` air through theradiator, the radiatoryis preferably arrange'dw-ithin af shell ofmore orv less elaborate'designwhich requiresspecial manufacturing facilities', and it is desirablethat the.

same type of shell beladaptable todifferenttractor models, for instance,to four-Wheel and threewheel tractors; of i substantially' thefsamehorsepower rating.

It is a further object of the invention to provide a tractor frontassembly; comprising-an improved steering gea'riin combination'with .alradiator and shell ofavailableconstruction,whichl front assembly maybeusedin .place oflanothervv front-assembly including-'a radiator and shell of'v said available construction, `the radiator 'shelli'of thesubstitute front assembly being'fittedto the steering truck withoutsubstantial alteration f or modication, so that. the sameImanufacturing# facilities may be used-for the` radiator shellsof bothfront assemblies.

These and other objects.- and advantages of the invention Will beapparent from fthe following description-of alpreferredembodirnent ofthe invention shown in the accompanying drawings;

Referring to the drawingain- Whichlike reference characters designatethe same orsimilar parts in the several views:

Fig. l is a top `viewof a tricycle type tractor.;

Fig. 2 isv aside view ofthe-tractor showninv Fig. 1;

Fig. 3 is an enlargedfront-view, Apartly insection on line III- III ofFig. 2, of` thefront end of the tractor shownin Figs, 1 and 2; and.`

Fig. 4 is a side view, partly in section,` ofpart` of the assembly shownin Fig. 3.

As is customary in tricycle type tractors, the tractor shown in Figs. 1and 2 has a pair of closely spaced front Wheels l and g, and apairA Forpurposes of.

of widely spaced rear wheels 3 and 4. The rear wheels are mounted on anupwardly arched rear axle structure 6 which has a central gear casing 1enclosing transmission and differential mechanisms. Secured to thecentral gear casing 1 and extending forwardly therefrom s a torque tubecasing 8 which is supportingly connected at its forward end with thecylinder block of an internal combustion engine 9, suitable powertransmitting mechanism being enclosed in the torque tube casing and rearaxle structure for driving the rear wheels 3 and 4 of the tractor fromthe engine 9.

Secured to the forward end of the cylinder block of the engine 9, asshown in Figs. 3 and 4, is a housing I I which forms the upper part ofthe front steering truck of the tractor. The housing I I has verticalfront, side and rear walls, and a pair of rearwardly extending bracketsI2 and I3 which are integrally formed with the left and right sidewalls, respectively, of the housing and by means of which brackets thehousing is connected to the engine 9. Each of the brackets i2 and I3 hasa laterally extending wing portion with a flat vertical rear surfaceabutting a corresponding fiat vertical front surface of the cylinderblock, and a number of bolts I4 passing through holes in the wings ofthe brackets are threaded into the cylinder block of the engine tosupportingly connect the housing II with the engine 9.

Secured to the bottom of the housing I`I by means of a series of VboltsI6 is a vertically disposed downwardly tapering housing I1 which formsthe spindle guide of the front steering truck of the tractor. The upperhousing II has a circular bottom opening I8 and the lower housing I1 hasan annular shoulder I9 at its upper end by means of which the housing I1is piloted on the housing II. Shims 2| for purposes of adjustmentexplained hereinbelow, areinterposed between the housing II and an upperiiange 22 of the housing I1, and the bolts I6 extend through holes inthe flange 22 and in the shims 2i, and are screwed into tapped holes ofthe housing II.

A vertical steering spindle 23 extends axially through the housing I1and terminates at its upper end within the housing II. A cambered axle24 is secured to the lower end of the spindle 23` by welding, and theclosely spaced front wheels I and 2 are journaled on opposite ends ofthe cambered axle, the wheels being rubber tired and extending upwardlyto a level below but in proximity to the upper housing II of the frontsteering truck. The welded construction of the spindle and axle assemblyis the subject of a copending application Serial No. 402,918 led on July18, 1941, by Conrad E. Frudden.

A short sleeve 26 surrounding the spindle 23 above the axle 24 andsecured thereto by welding, forms an abutment for the inner race of aconical roller bearing 21, the outer race of which is fitted into acylindrical recess at the lower end of the housing I1. The gap betweenthe sleeve 23 and the lower end of the housing I 1 is closed by a seal28. Another bearing for the spindle 23, in axial alinement with theroller bearing 21, is formed in an upper part of the housing I1, asshown at 29, the spindle 23 being rotatably fitted into an axial bore ofthe housing I1 at the upper end of the latter. A cork seal 30 at thelower end of the upper bearing 29 prevents undesirable seepage oflubricant from the upper housing past the bearing 29.

The mechanism for transmitting steering movements to the spindle 23comprises a steering crank 3| which is journaled in a bearing boss 32 ofthe housing II. 'Ihe bearing boss 32 extends outwardly from the sidewall of the housing II at the left side of the tractor, and the steeringcrank 3| has a shaft 33 which is mounted in an axial bore of the bearingboss, by means of bearing sleeves 34 and 36, for rotation about ahorizontal axis extending transversely of the tractor. At the outer endof the bearing boss 32 the bearing for the shaft 33 is protected by aseal 35. Secured to the inner end of the shaft 33 within the housing I Iis a. bevel gear segment 31 which has a, hub embracing the inner end ofthe shaft 33, a key 38 within the hub retaining the gear segment andshaft against rotation relative to each other, and a set screw 39 on thehub retaining the gear segment 31 in axially fixed position on the shaft33. y

The gear segment 31 meshes with a bevel gear 4I which is secured to theupper end of the steering spindle 23 within the housing II. The hubofthe bevel gear 4I has internal splines which cooperate with externalsplines on the upper end of the spindle 23 to secure the bevel gear andspindle against rotation relative to each other, and a washer 42 on topof the bevel gear 4I is retained by a bolt 43 which is threaded into anaxial tapped bore of the spindle 23. Axial movement of the spindle 23 inan upward direction relative to the housing I1 is limited by the conicalroller bearing 21, and axial movement of the spindle 23 in a. downwarddirection relative to the housing I1 is limited by engagement of the hubof the bevel gear 4I with the housing I1, a recess in the upper portionof the housing I1 affording a horizontal thrust surface 44 forcooperation with a flat end surface of the hub of the bevel gear 4I. Theaxial play of the spindle 23 within the housing I1 is adjusted by meansof shims 46 under the washer 42, the shims being of a diameter to iitinto the splined bore of the bevel gear 4I and being centered on thespindle 23 by means of the bolt 43. An increase of the number of shims46 under the washer 42 increases the axial play of the spindle 23relative to the housing I1, while a decrease of the number of shims 46decreases the axial play of the spindle 23, and in assembling thesteering truck just enough shims 46 are used to insure free running ofthe roller bearing 21 without appreciable axial play of the spindle 23relative to the housing I1. A lock washer 41 between the head of thebolt 43 and the washer 42 secures the bolt after it has been tightenedto compress the shims 46.

It will be noted that the lower housing I1 of the steering truck,together with all parts mounted thereon including the bevel gear 4I, maybe removed as a unit from the upper housing II after removal of thebolts I6 which secure the upper housing I I and the lower housing I1together. For convenience of assembly, the bevel gear 4I is preferablymounted on the steering spindle 23 prior to the installation of saidlower unit on the upper housing II, and the proper number of shims 46 toinsure free running of the roller bearing 21 without appreciable axialplay of the spindle 23 are also preferably installed prior to themounting of the lower unit on the housing II.

The steering crank 3I together with the bevel gear segment 31 ispreferably mounted on the housing II 'prior to the mounting of the lowerment 31 into the housing II and to aford access' to the set screw 39after the shaft 33 lhas been slid into the hub of the segment throughthe bearing boss 32. The hub of the bevel gear seg-` ment 31 has a planeend surface adjacent'to a vertical inner thrust surface 48 of thehousing II, the surface 48 serving as an abutment which may be engagedby the hub of the bevel gear segment 31 to limit axial displacement ofthe bevel gear segment in a direction awayirom the axis of the bevelgear 4 I.

The lower unit including the housing I1 is mounted on the upper housingI I after the steering crank 3l and bevel gear segment 31 have beeninstalled on the latter as described hereinbefore, and in bringing thelower unit in position on the housing II the teeth of the bevel gear 4Iare meshed with the teeth of the bevel gear Asegment 31. Forsatisfactory operation` of the bevel gear connection vbetween thespindle 23v and the steering crank 3i it is necessary that the depth ofmesh of the bevel gear 4I with the bevel gear segment 31 be accuratelyadjusted, and this may be done by increasing or decreasing the number ofshims 2l which are interposed, as mentioned hereinbefore, between theflange 22 of the housing I1 and the bottom of the upper housing II. Thethrust surface 4 on the housing I1 and the thrust surface 48 on thehousing II limit axial displacement of the bevel gear 4I and of thebevel gear segment 31, respectively, to which displacement these gearelements are subjected due to their mutual reaction when the steeringcrank 3l is rotated for transmitting steering movements to the spindle23, and the necessary number of shims ZI are used to insure the correctkdepth of mesh of the bevel gear 4I with the bevel gear segment 31 whenthe hub of the bevel gear 4I andthe hub of the bevel gear segment 31 arein contact, respectively, with the thrust surfaces 44 and 5B. It will benoted that the-depth of mesh of the gear elements of the bevel gearconnection within the housing II may be adjusted, by means of the shims2 I, independently of axial adjustment of the spindle 23 relative to thehousingrI1 by means of the shims 46.

Instead of two closely spaced front wheels such as shown at I and 2 inthe drawings, tricycle tractors are sometimes equipped with a singlefront wheel, and in that case the single front wheel is preferablymounted, according to accepted'practice, in a fork which carries arelatively short Vertical spindle at its upper end. A transversesteering crank and abevel gear arrangement corresponding to the steeringcrank 3| and bevel gear arrangement described hereinbefore may be usedto transmit steering movements to the relatively short steering spindleof such a wheel fork, or to any other vertical steering spindle mountedon the housing II. A short steering spindle of a wheel fork, asmentioned,

or for any other front support, may be mounted in upper and lowerbearings of the housing II, and an opening 43 for the reception of suchan upper bearing is shown in Fig. 3 in alinement with the axis of thesteering spindle 23.

Referring to Figs. 1 and 2, a hand wheel 5I for steering the tractor ismounted at the rear end of a rotatable steering column 52 within reachfrom an operators seat 53, The forward end of the steering column 52 ismounted in the Cil housing 540i a worm and gear steering unit ofstandard automotive'design, which housing'is secured to the torquetubecasing 8in rear-of vthe engine 9. A worm56 which is part of thestandard worm and gearA unit is connected with the steering column 52and meshes with a worm gear segment 51 which is also a par-'tof thestandard worm and gear unit. The segment 51 is secured to a cross shaft58 whichprojects from the -housing 54 at the left side of 'the tractor,the shaft 58 being rotatable on a horizontal axis whichextendsftransverselyof the tractor substantially parallel to theshaft 33of the steering crank 3l. The cross-shaft` 58 carries a steering arm 59at its outer end, and rotation of the cross-shaft 58` by operation ofthe hand wheel 5I is transmitted to the steering crank 3l by a link 6Iwhich' is pivotally connected to the free end of the steering arm 59 bymeans of a ball and socket joint 62. Secured to the'outer end of theshaft 33 of the steering crank 3l Vis a crank arm 63 which is pivotallyconnected at its free end to the forward end of the link 6I by vmeans ofa ball and socket joint 64.

Figs. 1 and 2 show the -front wheels I and 2 positioned for straightahead travel of the tractor, and it will be note-d from Fig. 2 that thecrank arm 63 is so arranged as to occupy an upn wardly extendingposition during straight ahead travel of the tractor. Similarly, therearward steering arm 59 on the cross shaft 58 is so arranged as tooccupy an upwardlyextending position duringstraightahead travel of thetractor. In order to steer the tractor from a straight ahead course tothe left the hand wheel 5i is turned anti-clockwise, with reference toan operator on seat 53, and, as a result, the steering arm 59 and thecrank arm 63 are swung forwardly from the position `in which they areshown in Fig. l2. Rotation of the-shaft 33 of the steering crank 3l, dueto forward movement of the crank arm 63,v is transmitted to the steeringspindle 23 through the bevel gear segment 31 and bevel gear 4I which areso meshed as to swing the Iwheels I and 2 to the left by forwardswinging movement of the crankarm 63. On the other hand, turningmovement of the hand wheel 5! in a clockwise direction, with referenceto an operator on seat 53, causes steering movement of the wheels I and2 to the right, the steering arm 59 and the crank arm 63, being swungrearwardly fromthe positions in which they are shown in Fig. 2, if thetractor is steered from a straight aheadcourse to the right. The link 6Iis reciprocated endwise longitudinally of the tractor by the describedmanipulation of the hand wheel 5I in opposite directions.

The gear ratio between the bevel' gear segment 31 and the bevel gear 4Iis such that forward swinging movement of the steering arm 59, from theposition in which it is shown in Fig.' 2, through an angle of about 40degrees swings the front wheels from the straight ahead position throughan angle of about 65 degrees,V and the crank arm 53 and the steering arm59 are so proportioned and arranged relative to each other that thefront wheels are swung through an angle of about 65degrees to the rightby rearward swinging movement of the steering arm 5B, from the positionin which it is shown in Fig. 2, through an angle of about 40 degrees tothe rear. Due to this arrangement the front wheels vI and 2 may safelyand without substantial effort be swung from one/'extreme steeringposition to the other without moving the crank arm-63 or the`steering-arm 59-and the link 6I undesirably close to a dead centerposition. In the extreme for-j ward or rearward positions to which thecrank arm 63 may be swung for steering, its free end is spaced asubstantial distance from the closest point of the periphery of thefront wheel I, so that there is no danger of the crank arm 63 or link 6|being struck by the tire of the front wheel I when the front wheels areswung to one or the other extreme steering position.

A radiator 66 for the internal combustion engine 9 is mounted on thefront steering truck of the tractor, as best shown in Figs. 3 and 4. Theradiator is seated on a support comprising a channel shaped cross bar 6land web plate 68 secured to the flanges of the bar 6l by welding. Theplate 68 rests on top of the housing II and is retained thereon in fixedposition by bolts 69 which are threaded into the top wall of the housingII. Bolts I'I and I2 retain the radiator 66 in an upright position onthe cross bar 6l.

The radiator 66 is surrounded by a sheet metal structure I3 which formsa shell for the radiator and which has a large screened front openingfor the admission of air to the radiator. A shutter, not shown, ispreferably arranged within the shell for regulating the passage of airthrough the radiator 66. As shown in Figs. 3 and 4, side walls I4 and'I6 of the radiator shell are connected by a curved bottom wall 'I'I,and a front wall 'I8 of relatively short height merges with the sidewalls 14, I6 and with the bottom wall TI. The lower part of the radiatorshell overlaps the supporting brackets I2 and I3 of the upper housing II of the front steering truck, and the housing II itself extendsupwardly into the radiator shell through a suitable cutout in the bottomwall l1 of the shell. A side opening 'I9 in the lower part of the shellaffords a passage for the shaft 33 of the steering crank 3ltherethrough. The shell is secured to suitable lugs of the brackets I2and I3 by means of screws 8l, and the side walls 'I4 and 'I6 of theshell are connected with side portions of the radiator 66 by a series ofscrew connections 82, one of which is shown in Fig, 4.

The crank arm 63 of the steering crank 3| is offset outwardly as shownin Fig. 3 and spaced laterally from the side wall 'I4 of the radiatorshell to provide clearance for the ball and socket joint 64 by which thelink 6I is connected to the crank arm 63, and which ball and socketjoint is arranged at the inner side of the crank arm 63. The crank arm63 may therefore be moved back and forth about the axis of the shaft 33through a relatively large range of swinging movement withoutinterference with the radiator and its shell. The link 6I extendslongitudinally of the tractor along the engine 9, and relatively littlespace at the side of the tractor is required for operation of the link6| and of the crank arm 63, since the latter swings in a vertical planewhich extends longitudinally of the tractor at the left side of thelatter. The arrangement of the crank arm 63 and the link 6I at the sideof the tractor has been found not to interfere objectionably with themounting of attachments or implements on the tractor or with convenientvisibility of the ground in proximity to the tractor from the operatorsseat 53.

The tractor front assembly herein disclosed is particularly adapted foruse in providing a` tri-- cycle type tractor as a companion to afourwheel type tractor which has a number of parts in common with thetricycle type tractor shown herein, such as the engine 9, radiator 66,torque tube casing 8, gear casing 'I and enclosed mecha- 75 nism, theoperatorsjseat'53 and its mounting, the fuel tank 83 and its mounting,the engine hood 84, and other parts. Such a companion four-Wheel typetractor is shown, for instance, in application Serial No. 274,164, filedMay 17,

mentioned side opening 79 for the shaft 33 ofthe steering crank 3|,whereas the shell as used in the companion four-wheel type tractor isdevoid of such bottom cutout and side opening. The dies for making theradiator shell represent a substantial investment in manufacturingfacilities, and the steering mechanism disclosed herein has anappreciable advantage from a manufacturing standpoint in that its userequires no change of the radiator shell of the companion four-wheeltractor, except for the mentioned minor alterations at the lower part ofthe shell, which may be made at a relatively low cost.

While in the foregoing a preferred embodiment of the invention has beendescribed in detail with reference to the drawings, it should beunderstood that it is not intended to limit the invention to the detailsof construction herein shown and described for various modicationswithin the scope of the appended claims may occur to persons skilled inthe art.

It is claimed and desired to secure by Letters Patent:

1. In a tractor having a forward engine unit, a housing forming part ofa steering truck supportingly connected with said engine unit, asteering spindle having a portion within said housing on an uprightaxis, a steering crank having a shaft portion extending transversely ofthe tractor through a wall portion of said housing at one side of thetractor and a crank arm at said one side of the tractor outside of saidhousing, a bevel gear connection between said spindle and shaft withinsaid housing, means associated with said housing for rotatablysupporting said spindle and shaft and for preventing axial displacementof said spindle and shaft due to the reaction of the gear elements ofsaid bevel gear connection, and actuating means for said steering crankincluding an endwise reciprocable link at said one side of the tractorextending longitudinally of the latter and pivotally connected at itsforward end to the free end of said crank arm.

2. In a tractor, a forward power plant including an internal combustionengine and a radiator in front of said engine, a housing supportinglyconnected with said engine and underlying said radiator, a steeringspindle having a portion within said housing on an upright axis ahead ofsaid engine, a steering crank having a shaft portion extendingtransversely of the tractor through a wall portion of said housing atone side of the tractor, a bevel gear connection between said spindleand shaft within said housing, said steering crank having a crank arm atsaid one side of the tractor outside of said housing arranged to occupyan upwardly extending position during straight ahead travel of thetractor and being spaced laterally from said radiator to permitunobstructed fore and aft swinging movement of said crank arm forsteering the tractor to the right and left, and actuating means for saidsteering crank including an endwise reciprocable link at said one sideof the tractor extending longitudinally of the latter along said engineand pivotally connected at its forward end to the free end ci said crankarm.

3. In a tractor, a forward power plant including an internal combustionengine and a radiator in front of said engine, a housing supportinglyconnected with said engine and underlying said radiator, a shell forsaid radiator having lower portions laterally overlying said housing, asteering spindle having a portion within said housing on an upright axisahead of said engine, a steering crank having a shaft portion extendingtransversely of the tractor through a wall portion of said housing andthrough one of said lower portions of said shell at one side of thetractor, a bevel gear connection between said spindle and shaft withinsaid housing, said steering crank having a crank arm at said one side ofthe tractor outside of said radiator shell arranged to occupy anupwardly extending position laterally of said radiator shell duringstraight ahead travel of the tractor and being spaced laterally fromsaid radiato1` shell to permit unobstructed fore and aft swingingmovement of said crank arm for steering the tractor to the right andleft, and actuating means for said steering crank including an endwisereciprocable link at said one side of the tractor extendinglongitudinally of the latter along said engine and pivotally connectedat its forward end to the free end of said crank arm. WALTER F.STREHLOW.

